Imagine that the government required people to wear a nice suit in public spaces like sidewalks, airports, and parks. Or required a precise haircut (e.g., within the last three days). Or imagine that signs had to be most easily read in latin. Or that Mormon sermons were loudly broadcast. Such policies would reduce the rate of crime and related complaints in public spaces, by imposing higher costs on the sorts of people who commit crimes (and on many others). Is that a good enough reason to implement such policies? Now consider that some public spaces play classical music to push away undesirables:

The Port Authority is one of many public spaces across the country that uses classical music to help control vagrancy: to drive the homeless away. … [In] the mid-1980s … a 7-Eleven began playing music in the parking lot as a deterrent to the crowds of teenagers congregating there. Plenty of stores continue to use the technique. … In 2001, police in West Palm Beach, Fla., blasted Mozart and Beethoven on a crime-ridden street corner and saw incidents dwindle dramatically. In 2010, the transit authority in Portland, Ore., began playing classical music at light-rail stops, and calls to police dropped. When the London Underground started piping classical music into its stations in 2005, physical and verbal abuse by young people declined by 33 percent. … Some sources report that Barry Manilow is as effective as Mozart in driving away unwanted groups of teens. (more)

The basic question: when is it ok for the government to impose costs on some subset of people in public, because that subset contains a higher fraction of those who commit crimes? Should there be any limits on the types of people a government can favor in public spaces?